摘要

猪场废水（SW）是环境中产生抗药性基因的重要来源。然而，很少有研究评估在整个废水处理过程中ARGs的发生和去除，以及随后的农田应用。本研究探讨了污水综合处理系统及其受纳土壤中的ARGs概况，以及它们与SW参数和细菌群落的关系。结果表明，磺胺类、四环素类和氨基糖苷类耐药基因在SW中占优势。经处理后，SW中总ARGs的相对丰度降低了84%。在SW处理单元中，厌氧消化、一次沉淀和人工湿地有助于去除ARGs，二次沉淀增加了总的ARGs丰度。SW经农田灌溉处理后，土壤中ARGs的含量持续增加，这可能是由于ARGs潜在的细菌宿主的繁殖和高频率的基因水平转移导致的。冗余分析表明，总ARGs的相对丰度与全氮、总磷、抗生素和细菌群落显著相关。细菌群落的变化是SW处理过程中ARGs变化的主要驱动因素。我们的结果强调了SW灌溉处理对农业环境抗生素抗性的变化有显著影响，有助于改善SW灌溉处理系统，更好地控制抗生素抗性。

Swine wastewater (SW) represents an important source of antibiotic resistance genes (ARGs) in the environment. However, few studies have assessed the occurrence and removal of ARGs in the whole wastewater treatment process followed by its farmland application. This study investigated the ARGs profiles in an integrated SW treatment system and its receiving soil, as well as their relationships with SW parameters and bacterial communities. Results revealed that sulfonamide, tetracycline and aminoglycoside resistance genes were dominant in SW. The relative abundance of total ARGs in SW was reduced by 84% after the treatments. Among the SW treatment units, anaerobic digestion, primary sedimentation and constructed wetland contributed to ARGs removal while secondary sedimentation increased the total ARGs abundance. Farmland irrigation of the treated SW resulted in enrichment of persistent ARGs in the receiving soil, which might be attributed to the propagation of potential bacterial hosts and high horizontal gene transferability. Redundancy analysis indicated that the relative abundance of total ARGs was significantly correlated with total nitrogen, total phosphorus, antibiotics and bacterial communities. The shift in bacterial community was the major driving factor for ARGs alteration during SW treatment process. Our results highlight the effect of treated SW irrigation on the antibiotic resistome in agricultural environment, and can contribute in improving SW treatment system for better antibiotic resistance control.

https://www.sciencedirect.com/science/article/pii/S0048969720311657